The present invention relates to a watch case-band comprising a crystal, a frame designed to house a movement equipped with hands, and a base fastened removably to the frame, with the bottom edge of the frame having two diametrically opposed undercuts that each accommodate one end of the band, the shape of the undercut being essentially the same as the shape of the band inserted therein, and the base being shaped to cover the undercuts when the case is closed.
A watch case of the type described above is disclosed in U.S. Pat. No. CH-A-355 095. The patent describes a frame in which two undercuts or recesses have been fashioned. Within each of the undercuts is inserted a band end that flares into a dovetail shape and is held within the undercut by virtue of the fact that the flared end has the same shape as the undercut. The band is held in place axially when the base of the case is applied to the underside of the frame. This arrangement shares with the present invention the advantage of concealing the entire system for attaching the band to the case, thus creating the illusion that the band is of a piece with, and not separate from, the
However, the abovementioned patent has several drawbacks. The first is that it requires special flared band ends. The flared portion may either be integral with, or connected to, the rest of the band, but either way it prevents the use of standard band ends with continuous or straight edges such as are found presently on the market. The second drawback is that it requires complicated recesses to be machined into the frame, which may be very difficult to accomplish if the frame is made of substances such as ceramics that are not easily susceptible to machining. A third drawback is that the attachment will not withstand the high tensile stresses that may be exerted on the band, since in such cases the band, which is typically made of leather or plastic, may become deformed and be pulled out of its housing.
In one particular arrangement, an attempt was made to retain the band by means of pins integral with a molded watch crystal and a ring screwed onto the base of the frame. This construction, described in document JP-U-1 149 226, has the disadvantage of being fragile, since the plastic pins break easily. It is also complicated, simply due to the presence of the ring.
Other objects of the invention and its mode of operation and construction will become apparent upon consideration of the following description and the accompanying drawing wherein embodiments are illustrated solely by way of example.